Rumors are swirling about the book, Blond Ambition: The Untold Story Behind Anna Nicole Smith's Death, due out next week. TMZ has heard Cosby will say she has documents that prove Larry Birkhead essentially bought the baby from Howard K. Stern.
Birkhead says, "OK! is on notice those allegations are false, and if they print them as truth, they will be sued as well." Birkhead adds, "I'll go after any media outlet that prints those lies from that book."